1. Field of the Invention
This invention relates to an endoscope utilized for the diagnosis and inspection of a living body, and mainly, a body cavity and the interior of a hollow organ in a human body.
2. Description of the Prior Art
Heretofore, there have been widely utilized fiber scopes for diagnosis and inspection of a living body, and mainly, a body cavity and the interior of a hollow organ in a human body such for example as the interiors of an upper digestive tract from a gallet through a stomach to a duodenum, a small intestine and a large intestine, and as apparatuses for medical treatment.
However, since the fiber scope of the type described is to be directly inserted into a human body through a body cavity, various troubles may occur when the fiber scope is inserted into an organ disposed in a deep portion of the body. When a fiber scope for the small intestine is to be inserted into the small intestine through an oral cavity or an anus for example, if the fiber scope is pushed in, then the fiber scope does not advance in the small intestine, because the small intestine is afloat on a mesentery. Then, the small intestine advances together with the fiber scope, and, if the fiber scope is further forcedly pushed in, then there may be a danger of breaking the small intestine. On the other hand, when a fiber scope for the large intestine is inserted through the anus, if the fiber scope is forcedly pushed into the large intestine, then a sigmoid colon located upwardly of a rectum may be broken.
Therefore, except for the above-described method of forcedly inserting the fiber scope into the body, there have heretofore been practised methods of insertion including a sonde method of inserting the fiber scope through the utilization of peristaltic motion of the intestines, a rope-way method, in which a string having a diameter of about 2 mm is swallowed by a patient and a fiber scope is inserted by drawing the string discharged by the patient the next day, and the like. However, both the sonde method and the rope-way method are disadvantageous in that a long period of time is required for the insertion of the fiber scope and the insertion causes pains to the patient for that long period of time.
Now, in the specification of French Patent No. 2481915, there is disclosed an apparatus having a so-called self-running device, in which a pulley is provided on the outer surface portion of a head of fiber scope and a belt being in frictional contact with the body wall surface is guided around this pulley.
According to the French Patent, the insertion of the head can be made for a short period of time by the turning of the belt. However, since the pulley is considerably projected from the outer surface of the head, with the result that the head becomes large sized, so that the pains suffered by the patient should not necessarily be alleviated. Moreover, the apparatus according to the French Patent is disadvantageous in that, when the fiber scope is inserted into a portion to be inspected such as a sigmoid colon, a mucous coat of the intestine is liable to be hurt, thus resulting in unsatisfactory safetly.
In Japanese Patent Kokai (Laid-Open) No. 22024/83, there is disclosed a fiber scope, in which a pulley for supporting a belt being in frictional contact with the body wall surface is provided in a head and the belt is extended through a hole formed in this head portion.
In the fiber scope according to the Japanese Patent Kokai (Laid-Open) No. 22024/83, the provision of the pulley in the head makes it possible to lessen the value of the aforesaid projection. However, the provision of a drive means for turning the pulley in the head increases the head accordingly, whereby the pains suffered by the patient still cannot be removed.